2 new filters for the next release

sauron · January 24, 2018, 12:04pm

For the next release would you consider adding two filters available in Kdenlive.

Cartoon.

Charcoal.

brian · January 24, 2018, 2:06pm

Seems like a reasonable request. I’ll look into it.

sauron · January 24, 2018, 6:17pm

Cool.

brian · January 25, 2018, 2:38am

So i looked at the two filters. It seems like the parameters are not very intuitive. I’m hoping we can rename or limit the parameters somehow to make them easier to use.

For the cartoon filter, there are two parameters: “Level of Trip” and “Difference Space”. I don’t understand what those mean. Can you suggest better names? Also, it seems that if I change either of them, the whole thing gets messed up. Can you offer what would be the “useful” range for those values so that we can limit the ranges to only useful values?

For the charcoal filter, the parameters are “horizontal scatter”, “vertical scatter”, “scale” and “mix”. I have the same problem with those - they don’t seem intuitive. I think that horizontal/vertical scatter could be named something like “Line height” and “line width”. I’m not sure what scale does. “Mix” seems to add color - so why not call it “color”? Can you suggest better names for these and maybe provide your understanding of their purpose? At least the ranges for the Charcoal filter seem to make sense - do you agree? Or should we limit the parameters in any way?

sauron · January 25, 2018, 3:03am

I just used the filters in Kdenlive one time for a video project. They worked well for the video.

I have no idea what those mean either. I just used the cartoon filter with it’s defaults.

I am not a programmer or developer and really am not qualified to suggest anything about these filters.

Apologies for not being more helpful.

brian · January 25, 2018, 3:06am

You are better than a developer: you are a user! You are the one who knows what is useful. Would you be willing to try the parameters and see if you find them useful? If neither of them are useful, I could implement the filter with no parameters. That might be the most user friendly thing to do.

sauron · January 25, 2018, 3:31am

I will try the parameters provided I can install and use the filters in Shotcut without having to compile anything. I have no compilers on my system and I’m not really able to use them even if I had them.

brian · January 25, 2018, 3:36am

I’m sorry, I meant for you to use them in Kdenlive. That is how I was trying them out.

sauron · January 25, 2018, 3:43am

Not sure I under stand what you mean. I have used both filters in Kdenlive once. I’ve also found that most of the parameters in Kdenlive are not very intuitive and need to be applied and reset a few times before a good result is achieved.

That’s why I use Shotcut. It’s easy to use and pretty intuitive. If I need complex effects I use Lightworks.

brian · January 25, 2018, 3:47am

So it seems you had the same experience with Kdenlive that I had The parameters were confusing. I don’t want to just copy that over to Shotcut, because then Shotcut would have the same problem. We need to determine what is useful in Kdenlive and bring that into Shotcut - while leaving out the parts that are confusing.

For both filters, what did you finally end up using in Kdenlive that worked for you? Also, what absolutely did not work?

sauron · January 25, 2018, 3:51am

Now I get it. I’ll reply with more detail later when I get a chance to look at what I ended up using in Kdenlive.

I used the cartoon filter with its default settings for a very small section of my project. I remember that I could not get a very good result by modifying the default setting. Still don’t understand what the Difference Space parameter is supposed to do. Level of Trip parameter seems like it might have something to do with some psychedelic effect. Difference Space parameter did not work for me at all.

Level of Trip could be changed to Intensity. I have no idea what to change Difference Space to. Maybe that parameter can be dropped.

Looking at the video in Kdenlive I used the Charcoal filter for quite a few clips. The results were good. I like it much better than the Cartoon filter. The Charcoal filter might be a good addition to Shotcut.

The settings that worked best for me were.

These were for that particular video.

If you add Charcoal filter to Shotcut I think Line Height and Line Width are good replacements for H and V scatter. Seems to me Scale makes the lines thicker so it could be called Scale or be changed to Intensity. Mix could be called Color MIx.

Keno40 · January 25, 2018, 11:44am

Just to help but I think you already saw that :
https://www.mltframework.org/plugins/FilterFrei0r-cartoon/
The 2 parameters are here to help doing the first step = > edge detect. Then the textures and colors are modified.

Someone already tried : Frei0r cartoon Filter (working code)

For charcoal, nothing in it…
https://www.mltframework.org/plugins/FilterCharcoal/

brian · January 25, 2018, 1:41pm

@Keno40 Good find!

For the Cartoon filter, we could use the implementation you found - with or without modification. I read the documentation for the two parameters and I just don’t know how I would explain to someone what they do. I would prefer to either exclude them (if the parameters aren’t really useful anyway) or rename them to something that I could explain to someone else.

The Charcoal filter does have parameters - but they aren’t documented in the MLT documentation. Here is where KDENLIVE defines them:

github.com

KDE/kdenlive/blob/master/data/effects/charcoal.xml

<!DOCTYPE kpartgui>
<effect tag="charcoal" id="charcoal">
	<name>Charcoal</name>
	<description>Charcoal drawing effect</description>
	<author>Charles Yates</author>
	<parameter type="constant" name="x_scatter" max="10" min="0" default="2">
		<name>Horizontal scatter</name>
	</parameter>
	<parameter type="constant" name="y_scatter" max="10" min="0" default="2">
		<name>Vertical scatter</name>
	</parameter>
	<parameter type="constant" name="scale" max="10" min="0" default="1">
		<name>Scale</name>
	</parameter>
	<parameter type="constant" name="mix" max="10" min="0" default="0">
		<name>Mix</name>
	</parameter>
	<parameter type="bool" name="invert" default="0">
		<name>Invert</name>
	</parameter>

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Keno40 · January 25, 2018, 2:09pm

I’ll try the cartoon filter tonight to see how I understand the “parameters” and see if they are usefull.

Keno40 · January 28, 2018, 10:40pm

Hi,
The cartoon filter is really interresting as it is.
Changing the “level of trip” is usefull from 0.90 to 1.
The “difference space” is active only when LoT is <1 and it produces different results depending of the luminosity of the image and the contrast. This setting is more related to line thickness but it not as simple.
I’ll let it as it is.

brian · February 2, 2018, 1:55am

Based on your comments and my own experience with “Cartoon”, I decided to focus on the charcoal filter.
I created a filter for you to try using the “charcoal” filter. But I renamed some things to make them more intuitive (I think).

Extract this file into your shotcut directory in Shotcut/share/qml/filters
sketch.zip (1.6 KB)
When you restart shotcut, the filter should now be in your list of video filters. It is named “Sketch”.

Let me know your thoughts. Would this be more intuitive than what is in KDENLIVE?

sauron · February 2, 2018, 2:14am

I don’t know if this is mean for me or Keno40. In any event I will try it shortly and report back.

I did try the cartoon filter that Keno40 found. Did not like it. Had weird results. Might give it another try later.

brian · February 2, 2018, 2:37am

I was hoping to get feedback from both of you And anyone else who might be interested.

sauron · February 2, 2018, 4:15am

It’s working very well. Functions pretty much the same as the charcoal filter in Kdenlive but the parameters are more intuitive. Very nicely done filter.

Made a quick video with it. Not the best but I think it shows the capabilities of Sketch.

Steve_Ledger · February 2, 2018, 4:58am

In Windows 10 it;s
Shotcut\share\shotcut\qml\filters